Apparatus and method for noninvasive chemical analysis

ABSTRACT

A method and apparatus are provided for magnetohydrodynamic acoustic-resonance, near-IR spectroscopy. The method includes a step of applying to a subject under study a magnetic field having a strength between 2,00-10,000 gauss, near-IR radiation having a wavelength between 800-3,000 nm and an acoustic wave having a frequency between 10 khz-1 Mhz. The method also includes the steps of inducing vibration of ions in the magnetic field and detecting an electric wave generated magnetohydrodynamically by the acoustic wave induced vibration of the ions. Next is the collecting of the electrical, acoustical and near-IR spectra and the analyzing of the collected spectra. The spectra is analyzed in a hyphenated, multidimensional fashion.

TECHNICAL FIELD

The present invention relates generally to a method and apparatus forthe chemical analysis of a selected specimen or subject through thesimultaneous utilization of acoustic-resonance waves and near-IRradiation alone or in conjunction with a magnetic field.

BACKGROUND OF THE INVENTION

Various analytic and diagnostic approaches have been devised fornoninvasive chemical analysis. Such approaches include, for example,near-IR spectrometry and acoustic-resonance spectrometry.

More specifically, as disclosed in copending U.S. patent applicationSer. No. 945,202, filed Sep. 15, 1992 and entitled APPARATUS AND METHODFOR ANALYZING TISSUE, (the disclosure of which is fully incorporatedherein by reference), near-IR spectrometry may be utilized, for example,to determine the presence and relative concentrations of cholesterol andlipoproteins in a human blood matrix. The article "Ultrasonic ResonanceSpectroscopic Analysis of Microliters of Liquids", Applied Spectroscopy,Volume 42, No. 3, 1988, pp. 526-529, describes a method of utilizingultrasonic resonance techniques for the identification of microliters ofliquids. This ultrasonic technology is also already used to sense thetypes and amounts of gasses in an air sample by detecting resonantfrequency shifts.

Up to the date of the present invention, however, near-IR spectrometryand acoustic-resonance spectrometry have only been utilized separatelyand not in combination. Advantageously, the present inventor has nowfound that the two techniques may be utilized together in a "hyphenated"fashion to achieve a surprising, synergistic and more powerful result.Specifically, ultrasound and near-IR light may be made to interact toprovide additional selectivity for targeted analytes in a sample.Further, the present inventor has found that the addition of powerfulmagnets adds a third dimension to the analysis by enabling detection ofultrasonically induced electrical currents in the sample. Thus, theconcentration of electrolytes in a specimen or subject undergoinganalysis may be determined accurately and noninvasively. Thisinformation may then be utilized to essentially eliminate near-IRspectral interference from water thereby enhancing the sensitivity andperformance of this novel analytical technique.

SUMMARY OF THE INVENTION

Accordingly, it is a primary object of the present invention to providea method and apparatus for combining near-IR spectrometry andacoustic-resonance spectrometry to provide enhanced analysiscapabilities that may, advantageously, be utilized in vitro or in vivo.Such capabilities allow noninvasive and nondestructive determination ofthe concentration of substantially any biological molecule or ion in anaqueous environment. This information may then be utilized in the earlydiagnosis of certain medical risks and disorders and therebyadvantageously allow early administration of effective treatment to apatient.

Still another object of the present invention is to provide a method andapparatus for magnetohydrodynamic/acoustic-resonance/near-IRspectrometry (MARNIR) wherein the specimen or subject is simultaneouslysubjected to the application of near-IR radiation, a tunable acousticwave and a magnetic field. Advantageously, spectral interference fromwater is mathematically eliminated by noninvasively determining thetotal concentration of electrolytes in the specimen or subject.Specifically, the ions are nondestructively vibrated with ultrasound ina magnetic field thereby inducing an electric current with an amplitudeproportional to the amount or concentration of electrolytes present.

Still another, more specific, object of the present invention is toprovide a new diagnostic method for quantification of cholesterol andlipoproteins in a noninvasive and nondestructive manner either in ablood specimen in vitro or in a mammal such as a human in vivo.

Additional objects, advantages and other novel features of the inventionwill be set forth in part in the description that follows and in partwill become apparent to those skilled in the art upon examination of thefollowing or may be learned with the practice of the invention. Theobjects and advantages of the invention may be realized and obtained bymeans of the instrumentalities and combinations particularly pointed outin the appended claims.

To achieve the foregoing and other objects, and in accordance with thepurposes of the present invention as described herein, a method andapparatus are provided for acoustic-resonance, near-IR spectroscopy. Inaccordance with this analytic and diagnostic technique, enhanced,nondestructive/noninvasive identification of nonelectrolytes (eg.nonelectrical conducting materials) in serum samples and the body ispossible. More specifically, the method for acoustic-resonance, near-IRspectroscopy comprises the steps of simultaneously applying to a subjectunder study near-IR radiation and an acoustic wave, collectingacoustical and near-IR spectra and analyzing the collected spectra.

Still more specifically, the near-IR radiation utilized has a wavelengthbetween 800-3000 nm. Preferably, this entire wavelength spectrum isapplied simultaneously and in parallel with equal weighting being givento each wavelength so as to ensure that any variations in absorbance atany wavelength for the subject undergoing study is observed. As alltissues and chemical analytes absorb light across all these wavelengths,with tissues and analytes absorbing only a little more at somewavelengths than others, this broad band parallel approach is necessaryto ensure that no unusual tissue or analyte is missed during study.Accordingly, the analysis is more accurate and complete. Further, as theanalysis is performed in parallel, the complete study may still becompleted in a sufficiently short time span to allow clinicalutilization of this technology.

The tunable acoustic wave that is applied to the subject under studypreferably has a frequency of between 10 khz-1 Mhz. Advantageously, bytuning the acoustic wave in accordance with the known characteristics ofthe analyte for which an assay or analysis is being completed, it ispossible to improve identification and quantification for that analyte.For example, similar apolipoproteins, such as apoA-I and apoA-II, may bemore readily distinguished in solution. Specifically, the acoustic waveform modulates the confirmation and hence the near-IR spectra of thesecompounds through hydrogen bonding. In addition, the acoustic wave maybe tuned to help to set the near-IR spectral baseline by establishingthe bulk density of tissue samples in vivo.

In accordance with yet another aspect of the method, the acoustical andnear-IR spectra that are collected are analyzed in a hyphenated,multidimensional fashion.

In accordance with yet another aspect of the present invention, amagnetic field is applied to the subject under study simultaneously withthe near-IR radiation and acoustic wave in order to providemagnetohydrodynamic, acoustic-resonance, near-IR spectroscopy or MARNIR.Specifically, the magnetic field, near-IR radiation and acoustic waveare all applied to the subject in independent planes that are orthogonalto one another. The addition of the powerful magnetic field adds anotherdimension to the analytical capability of the present invention byenabling detection of ultrasonically induced electrical currents in thesample. Accordingly, it is possible to overcome a notable limitation ofsimple near-IR spectrometry that is imposed by spectral interferencefrom water.

More specifically, the near-IR spectral bands of water change inresponse to temperature, pH and the concentration of other ions in thewater. These all effect the extent of hydrogen bonding. The spectra ofanalytes like cholesterol are easily obscured by changes in the waterspectrum which is the most intense spectrum observed in the near-IR. Asthe water interference can be removed mathematically from near-IRspectra if the total electrolytes can be determined, the present methodis particularly advantageous as the total electrolytes may be determinednoninvasively and nondestructively by vibrating the ions with ultrasoundand inducing an electrical current with an amplitude proportional to theamount of electrolytes present. As a result, enhanced sensitivity andperformance are provided efficiently and noninvasively to achieve morereliable and accurate quantitative analysis.

In the most preferred form of the invention, the magnetic field has astrength between 2000-10000 gauss. Such a field strength allows the ionsvibrated by the acoustic wave to produce a sufficiently strongelectrical current to allow reliable detection and accuratedetermination of ion concentration.

In accordance with yet another aspect of the present invention, anapparatus is provided for performing acoustic-resonance, near-IRspectroscopy. The apparatus includes means for irradiating the subjectwith near-IR radiation and means for simultaneously producing a tunableacoustic wave that is transmitted into and through the subject.Additionally, the apparatus includes means for collecting acoustical andnear-IR spectra that result. Means, such as a supercomputer, foranalyzing the spectral data in accordance with the algorithm describedabove is also provided.

Still further, an apparatus for performing MARNIR of a subject understudy also includes means for producing a magnetic field and means fordetecting electrical waves generated magnetohydrodynamically by theacoustic wave induced vibration of ions in the magnetic field. In thisway, the ion concentration of the subject/specimen may be noninvasivelydeduced. Further, means are provided for simultaneously collecting theelectrical spectra that result and this spectra is simultaneouslyanalyzed along with the acoustical and near-IR spectra for accurate andcomplete analysis.

Still other objects of the present invention will become apparent tothose skilled in this art from the following description wherein thereis shown and described a preferred embodiment of this invention, simplyby way of illustration of one of the modes best suited to carry out theinvention. As it will be realized, the invention is capable of otherdifferent embodiments and its several details are capable ofmodification in various, obvious aspects all without departing from theinvention. Accordingly, the drawings and descriptions will be regardedas illustrative in nature and not as restrictive.

BRIEF DESCRIPTION OF THE DRAWING

The accompanying drawing incorporated in and forming a part of thespecification, illustrates several aspects of the present invention, andtogether with the description serves to explain the principles of theinvention. In the drawing:

FIGS. 1a and 1b are schematic block diagrams illustrating the methods ofthe present invention;

FIG. 2 is schematical representation showing the orthogonal applicationof the acoustic resonance wave, near-IR radiation and magnetic field toa subject;

FIG. 3 is a schematical representation of the apparatus of the presentinvention; and

FIGS. 4 and 5 are histograms showing, respectively, the correlation andstandard error of estimate for cholesterol in aqueous solutionscontaining sodium ions.

Reference will now be made in detail to the present preferred embodimentof the invention, an example of which is illustrated in the accompanyingdrawing.

DETAILED DESCRIPTION OF THE INVENTION

Reference is now made to the schematic block diagram shown in FIG. 1adescribing the method of the present invention for simultaneousacoustic-resonance, near-IR spectroscopy. That method 10 includes theinitial step 12 of simultaneously applying to a subject under study bothnear-IR radiation and an acoustic wave. "Subject under study" is beingbroadly utilized to refer to a collected biological specimen held in avial or container that is undergoing in vitro analysis or a mammal suchas a human that is undergoing in vivo analysis.

Preferably, the near-IR radiation that is applied to the subject has awavelength of between 800 and 3,000 nm. Still more preferably, lightacross the full wavelength spectrum of 1,500-2,100 nm and, morepreferably, 800-3,000 nm is applied simultaneously and in parallel. Thisis done because major spectral changes indicating the presence of aselected analyte, such as low-density lipoprotein (LDL) may be observedin this range. In order to determine the presence of these low-densitylipoproteins with analytical precision it is desired to utilize lightacross the full spectrum indicated. This is because tissues and analytesabsorb light at all wavelengths across this range and different tissuesand analytes absorb only a little more at some wavelengths than others.As the chemical make-up of the subject under study is unknown, theparticular wavelength(s) where these differences occur are also unknownin advance. It is, therefore, necessary to analyze the entire range witheach wavelength being given equal weight in the analysis.

Further, this must be done simultaneously and in parallel to ensure aspeed of imaging necessary to make this method acceptable for clinicalapplications. Only in this way is it possible to avoid missing thepresence of unusual tissues or analytes of interest to the cliniciancompleting the study.

The acoustic wave applied to the subject preferably has a frequencybetween 10 khz-1 Mhz. Still more preferably, the frequency is tunable sothat the technician may perform a series of steps to enhance theperformance and sensitivity of the method and achieve sharply enhancedanalytical results. Specifically, the acoustic wave spectrum may, forexample, be patterned to help set the near-IR spectral baseline byestablishing the bulk density of the tissue samples in vivo. This maybest be done by, for example, using the ARS spectrum to determineacoustic velocity of the tissue by examining the magnitude of the phaseshifts observed in the sample signal at several ARS spectral peaks.

The acoustic wave spectrum may also be tuned and thereby utilized toimprove identification and quantification of similar analytes such asapolipoproteins (such as apoA-I and apoA-II) in solution. Morespecifically, their conformations and hence their near-IR spectra aremodulated through hydrogen bonding. This may be done by using a standingwave, which may be a compression or rarefaction, to make a largemolecule adopt a certain conformation.

Performed in combination with the application of the near-IR radiationand acoustic wave is the step 14 of collecting acoustical and near-IRspectra from the subject. These spectra are collected simultaneously andin parallel. Specifically, equal weight is given to each wavelength ofradiation over the applied 800-3,000 nm near-IR band spectrum at thefrequency of the acoustic wave being applied and collected.

The collected acoustical and near-IR spectra are then analyzed in ahyphenated, multidimensional fashion (step 16). More specifically, thespectral data is analyzed in accordance with the copyrighted 3N-BESTAlgorithm software as authored by Robert A. Lodder. Specifically, thecollected near-IR and acoustic wave spectra are digitized for analysison a processor such as an IBM 3090-600J super computer as available atthe University of Kentucky.

In accordance with yet another aspect of the present invention and asrepresented in the schematic block diagram shown in FIG. 1b, a magneticfield may be simultaneously applied (step 18) to the subject under studywith the near-IR radiation and tunable acoustic wave. Preferably, themagnetic field, near-IR radiation and acoustic wave are applied to thesubject in planes orthogonal to one another such as shown in FIG. 2.This spatial relationship is preferred because the acoustic wave shouldbe perpendicular to the magnetic field to maximize current flow, and thenear-IR light should be perpendicular to the acoustic wave in order toselectively sample conformations in compressions or rarefactions in astanding wave. For purposes of illustration, the orthogonal samplingarrangement being described is shown relative to a rectangular samplecell or vial in FIG. 2.

More specifically, the applied magnetic field preferably has a strengthof between 2,000-10,000 gauss while the near-IR radiation has awavelength between 800-3,000 nm and the acoustic wave has a frequencybetween 10 khz-1 Mhz. The addition of the powerful magnetic fieldfurnishes a third dimension to the analysis thereby enabling detectionof ultrasonically induced electrical currents in the subject.Advantageously, this ability makes it possible to overcome a notablelimitation of simple near-IR spectrometry that is imposed by thespectral interference from water.

Near-IR spectral bands of water change in response to changes intemperature, pH and the concentration of other ions in the water. Thisis because these all effect the extent of hydrogen bonding. As the mostintense spectrum observed in the near-IR is the water spectrum, thespectra of analytes, like cholesterol, are easily obscured by changes inthe water spectrum. This problem of obscured results may be avoided bymathematically removing the water interference from near-IR spectrawhere the total electrolytes can be determined. Advantageously, thepresent method allows the total concentration of electrolytes to bedetermined noninvasively and nondestructively by vibrating the ions withultrasound in the magnetic field, thereby inducing an electrical currentwith an amplitude proportional to the amount/concentration ofelectrolytes.

Specifically, the acoustic wave may be tuned to induce ion motion in themagnetic field (step 20). The moving ions, such as sodium ions, createan electrical current that is detected by electrodes (step 22). Bymeasuring the current continuously in a computerized pattern algorithmthe ion concentration is revealed thereby permitting accurate analysisof, for example, cholesterol and other analytes through the substantialelimination of near-IR spectral interference from water.

In combination with the simultaneous application of the magnetic field,near-IR radiation and tunable acoustic wave is the simultaneouscollecting of electrical, acoustical and near-IR spectra (step 24). Thisis followed by the analyzing of the collected spectra in the hyphenated,multidimensional fashion (step 26). Specifically, the 3N-BEST Algorithmsoftware is utilized.

The basic principle behind this software is to represent the completenear-IR, acoustic-resonance, and magnetohydrodynamic spectra of a sampleas a single direction vector in a thrice-augmented hyperspace with alength that is an asymmetric probability. The output of the 3N-BESTAlgorithm software can then be analyzed directly by discriminantanalysis or by traditional methods like partial least squares orprincipal component regression, or can be analyzed by more sophisticatedfull-spectra techniques like the BENDS algorithm.

Specifically, the acoustic spectrometers collect either 128, 452 or16,384 data points per spectrum. Thus, if the middle value is chosen asthe default, a single scan under the present method can be representedas a point in a 1605 dimensional space (701+452+452). If the data areanalyzed in a more accurate hyphenated configuration, one obtains a316,852 dimensional space (701×452×452). In this latter case the spectracannot be represented as a single line with peaks and valleys. Instead,each individual spectrum has to be drawn as a three-dimensional figure,making the display considerably more difficult.

The algorithm, however, does not require a display of individual spectrain order to produce an analytical result; that is, the identity andquantity of each constituent. Accordingly, when the present method isutilized to quantify cholesterol and lipoproteins simultaneously inserum samples and/or in vivo, sufficiently accurate analysis is possibleto advantageously allow, for example, accurate predictions of the risksof stroke in a patient. Additionally, the present method readily allowsthe effectiveness of a treatment regimen to be closely monitored andadjustments made as necessary in order to provide more effectivetreatment. Further, as the overall method minimizes sample handling aswell as time of analysis, measurements of in vitro specimens/samples, inparticular, are more accurate. This is because of a resulting reductionin degradation of the analyte (e.g. lipoprotein) being assayed.

In accordance with still another aspect of the present invention, anapparatus for conducting magnetohyrodynamic, acoustic-resonance, near-IRspectroscopy is schematically shown and will now be described withreference to FIG. 3. The apparatus 30 being described is designed for invitro analysis of, for example, a biological specimen contained in avial V. It should be appreciated, however, that a similar arrangementmay be utilized to analyze a subject such as a mammal in vivo.

As shown in FIG. 3, the vial V is positioned so as to rest at the bottomof a V-shaped slot 32 formed between a pair of opposed, samarium cobaltmagnets 34. Such magnets have a field strength of between 2,000-10,000gauss. Magnets of the type utilized are available, for example, fromEdmond Scientific, catalog No. A30,730 ring magnets, 8000 gauss.

As further shown in FIG. 3, a near-IR probe 36 is positioned beneath thesample vial V. A near-IR probe 36 of the type that may be utilizedincludes a tungsten-halogen lamp with wavelength selection beingaccomplished utilizing a concave holographic diffraction grating incombination with a lead sulfide (Pbs) or indium antimonide (InSb)detector cooled with liquid nitrogen. Commercially available near-IRprobes 36 may be obtained from a number of sources including,Bran+Luebbe, such as the Bran+Luebbe EDAPT 1. Preferably, the near-IRprobe 36 is capable of producing a light spectrum having a wavelength ofbetween 800-3,000 nm (at least 1,500-2,100 nm). Light over this fullspectrum is preferably applied simultaneously and in parallel to thespecimen in the vial V.

As further shown, the apparatus 30 also includes an acoustic wavegenerator/receiver generally designated by reference numeral 38. Theacoustic wave generator/receiver 38 includes transmitting piezo films40, 42 and receiving piezo film 44. Films that may be utilized for thispurpose include polyvinylidene fluoride films such as available fromAtochem Sensors, Inc. These films are capable of transmitting andreceiving a tunable acoustic waveform having a frequency of between 10khz and 1 Mhz.

After collecting and placing a biological specimen in the vial V, thevial is sealed and positioned in the V-shaped slot 32 between themagnets 34. A scan is then initiated. Accordingly, the specimen in thevial V is simultaneously subjected to a magnetic field of 8,000 gauss,near-IR radiation across a full spectrum of, preferably, 800-3,000 nmand a tunable acoustic wave having a frequency of between 10 khz and 1Mhz. The frequency of the acoustic wave that is chosen is usuallydetermined by the ultrasonic characteristics of the analyte for whichassaying or analysis is being completed. When assaying a specimen foroverall chemical make-up, a selected series of frequencies or a sweepthrough the full frequency range may be performed.

Advantageously, the acoustic wave that is transmitted through thespecimen in the vial V causes ions in the aqueous medium to vibrate.These ions, such as sodium ions, produce an electric current in themagnetic field as a result of their vibration. The resulting electricalspectra is collected by a pair of opposed magnetohydrodynamic electrodes(MHD electrodes) 46 placed beside the specimen vial V at 90° to thesamarium cobalt magnets 34. Such electrodes 46 may be constructed fromcommon electronics parts available from a number of sources. Gold orplatinum wire is preferred in the construction.

The resulting electrical spectra is collected simultaneously along withthe near-IR and acoustic wave spectra. Specifically as shown, thespectral data is collected and delivered along signal lines 48 foranalysis utilizing a processor such as a super computer 50. The 3N-BESTsoftware/algorithm analysis is then completed as required to provide thedesired quantitative assay.

In early experiments, the apparatus 30 described above has been utilizedto obtain experimental data from twenty-seven calibration samplescontaining various amounts of sodium chloride (0, 0.8752 and 1.75 mg/ml)and cholesterol (0, 1, 2, 3, 4 mg/ml). First, near-IR scans (e.g.near-IR spectroscopy alone) of five samples with the same range ofcholesterol concentrations from each of the three sodium ionconcentration groups were analyzed by complete linkage cluster analysis.The results showed that the observed near-IR spectrum of cholesteroldepends on the sodium concentration. Thus, the interference problemcaused by ion concentration shifting of the near-IR water spectrum wasdemonstrated.

In subsequent tests utilizing full MARNIR capabilities, the meanmagnetohydrodynamic signals observed at the op amp for the differentlevels of Na⁺ in solution were 0.8 volts for 0 mg/ml of Na⁺, 0.4 voltsfor 0.8752 mg/ml of Na⁺ and 0.6 volts for 1.75 mg/ml of Na⁺. The 0.8volt value for the 0 mg/ml Na⁺ concentration group actually results fromwhat is known as "antenna effect." Specifically, the no sodium,deionized water utilized acted as an insulator and caused the MHDelectrodes to function as antennas, picking up radiated radio frequencyenergy from the signal generator which was found to not be fullyshielded. Otherwise, the detected MHD voltage was found to be directlyproportional to sodium concentration thereby allowing the Na⁺concentration of a specimen to be accurately determined.

FIGS. 4 and 5 show how knowledge of the Na⁺ concentration provided byacoustics and magnetohydrodynamics as applied in this invention improvesthe ability to noninvasively determine cholesterol concentrations. Thefirst bar in each histogram shows the correlation (R²) and standarderror of estimate (SEE), respectively for cholesterol if Na⁺ levels areunknown. In the second, third and fourth bars, the correlation and SEEare given for each group of samples with known Na⁺ concentrationdetermined by the detected magnetohydrodynamic signal. In each case,knowledge of Na⁺ concentration improves that determination ofcholesterol. Because the test apparatus of the present invention thatwas utilized in these early studies was only a prototype with limitedsensitivity, the best signals and lowest errors in Na⁺ concentrationoccur when analyzing the high Na⁺ concentration group (1.75 mg/ml). Itshould be appreciated, however, that such a concentration level is stilllower than physiologic Na⁺ levels and, accordingly, utility of thismethod and apparatus for biological analysis is established.

In summary, numerous benefits have been described which result fromemploying the concepts of the present invention. Specifically, far moreefficient and precise quantitative analysis capabilities are providedutilizing the present method and apparatus. Specifically, the presenceof analytes may be determined in an accurate and efficient manner as thenear-IR spectral interference from water is substantially eliminated ina nondestructive manner. Advantageously, the quick and efficientnoninvasive and nondestructive approach of the present inventionfunctions to provide a diagnostic technique of considerable importancesuch as may be utilized to predict the risks of stroke, confirm theexistence of certain maladies and even monitor the effectiveness oftreatment procedures.

The foregoing description of a preferred embodiment of the invention hasbeen presented for purposes of illustration and description. It is notintended to be exhaustive or to limit the invention to the precise formdisclosed. Obvious modifications or variations are possible in light ofthe above teachings. The embodiment was chosen and described to providethe best illustration of the principles of the invention and itspractical application to thereby enable one of ordinary skill in the artto utilize the invention in various embodiments and with variousmodifications as are suited to the particular use contemplated. All suchmodifications and variations are within the scope of the invention asdetermined by the appended claims when interpreted in accordance withbreadth to which they are fairly, legally and equitably entitled.

I claim:
 1. A method for magnetohydrodynamic, acoustic-resonance near-IRspectroscoy, comprising the steps of:simultaneously applying to asubject under study (1) a magnetic field, (2) near-IR radiation and (3)an acoustic wave; generating electrical spectra magnetohydrodynamicallyby the acoustic wave induced vibration of ions in the magnetic field;collecting electrical, acoustical and near I-R spectra emitted from thesubject under study as a result of the simultaneously applied magneticfield, near-IR radiation and acoustic wave; analyzing the collectedspectra.
 2. The method set forth in claim 1, wherein said electrical,acoustical and near-IR spectra are all collected simultaneously.
 3. Themethod set forth in claim 2, wherein said magnetic field, near-IRradiation and acoustic wave are all applied to the subject under studyin directions orthogonal to one another.
 4. The method set forth inclaim 3, wherein said electrical, acoustical and near-IR spectra arecollected in a hyphenated multidimensional fashion.
 5. The method setforth in claim 2, wherein said electrical, acoustic and near-IR spectraare collected in a hyphenated multidimensional fashion.
 6. The methodset forth in claim 1, wherein said magnetic field, near-IR radiation andacoustic wave are all applied to the subject under study in directionsorthogonal to one another.
 7. The method set forth in claim 6, whereinsaid electrical, acoustical and near-IR spectra are collected in ahyphenated multidimensional fashion.
 8. The method set forth in claim 1,wherein said electrical, acoustical and near-IR spectra are collected ina hyphenated , multidimensional fashion.
 9. A method formagnetohydrodynamic, acoustic-resonance, near-IR spectroscopy,comprising the steps of:simultaneously applying to a subject under study(1) a magnetic field having a strength between 2,000-10,000 gauss, (2)near-IR radiation having a wavelength between 800-3,000 nm and (3) anacoustic wave having a frequency between 10 khz-1 Mhz; inducingvibration of ions in the magnetic field by application of the acousticwave and generating electrical spectra magnetohydrodynamically by theacoustic wave induced vibration of said ions; collecting electrical,acoustical and near-IR spectra emitted from the subject under study as aresult of the simultaneously applied magnetic field, near-IR radiationand acoustic wave; and analyzing the collected spectra.
 10. The methodset forth in claim 9, wherein analyzing of the collected near-IR spectrais performed by equal weighting of wavelengths across a near-IRradiation spectrum of between at least 1500-2100 nm.
 11. The method setforth in claim 10, wherein said magnetic field, near-IR radiation andacoustic wave are all simultaneously applied to said subject under studyin directions orthogonal to one another.
 12. The method set forth inclaim 11, wherein said electrical, acoustical, near-IR spectra arecollected simultaneously in a hyphenated, multidimensional fashion. 13.The method set forth in claim 9, wherein analyzing of the collectednear-IR spectra is performed by equal weighting of wavelengths across anear-IR radiation spectrum of between at least 800-3000 nm.
 14. Themethod set forth in claim 13, wherein said magnetic field, near-IRradiation and acoustic wave are all simultaneously applied to saidsubject under study in directions orthogonal to one another.
 15. Themethod set forth in claim 14, wherein said electrical, acoustical,near-IR spectra are collected simultaneously in a hyphenated,multidimensional fashion.
 16. The method set forth in claim 9, whereinsaid magnetic field, near-IR radiation and acoustic wave are allsimultaneously applied to said subject under study in directionsorthogonal to one another.
 17. An apparatus for performingmagnetohydrodynamic, acoustic-resonance, near-IR spectroscopy of asubject under study, comprising:means for producing a magnetic fieldapplied to said subject under study; means for irradiating said subjectunder study with near-IR radiation; means for producing a tunableacoustic wave that is transmitted into the subject under study; meansfor detecting and collecting electrical spectra generatedmagnetohydrodynamically by the acoustic-wave induced vibration of ionsin the magnetic field whereby ion concentration may be noninvasivelydeduced; means for collecting acoustical and near-IR spectra emittedfrom the subject under study as a result of the applied, near-IRradiation and acoustic wave; and means for analyzing the collectedspectra.
 18. The apparatus set forth in claim 17, including means forapplying said magnetic field, near-IR radiation and acoustic wave tosaid subject under study simultaneously and in directions orthogonal toone another.